Purification and identification of major soluble 40-kDa antigenic protein from Entamoeba histolytica: its application for serodiagnosis of asymptomatic amebiasis.

Abstract

One of the major soluble antigenic proteins of Entamoeba histolytica was purified to homogeneity and identified on a molecular basis. Its recombinant protein was expressed in Escherichia coli as a fusion protein with Shistosoma japonicum glutathione S-transferase. Apparent molecular weight of the purified antigenic protein was estimated to be 40-kDa and molecular-based analysis indicated that the purified protein was NADP+-dependent alcohol dehydrogenase (EhADH1). The application of the purified protein for the serodiagnosis of amebiasis was evaluated using an enzyme-linked immunosorbent assay applied to sera obtained from patients with amebiasis and healthy human controls. The purified protein was well recognized by the sera from asymptomatic amebiasis humans (22/22, 100%), whereas, it was less recognized by the sera from symptomatic amebiasis patients (5/16, 31%) with amebic colitis or liver abscess. To confirm the antigenicity of EhADH1, the recombinant glutathione S-transferase-EhADH1 fusion protein was also evaluated by the enzyme-linked immunosorbent assay using the same sera. The recombinant protein was also recognized by the sera from asymptomatic amebiasis humans (14/22, 64%) and less recognized by the sera from symptomatic amebiasis patients (2/16, 13%). These results suggest that the purified protein is applicable antigen for serodiagnostic screening of asymptomatic amebiasis humans.

• Authors: J Sanuki, K Nakano, M Tokoro, T Nozaki, E Okuzawa, S Kobayashi, T Asai
• Journal: Parasitology international (Parasitol Int) Vol. 50 Issue 2 Pg. 73-80 (Jul 2001) ISSN: 1383-5769 [Print] Netherlands
• PMID: 11438429 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Protozoan
• Antigens, Protozoan
• Epitopes
• Recombinant Fusion Proteins

Topics

• Animals
• Antibodies, Protozoan (blood)
• Antigens, Protozoan (chemistry, immunology, isolation & purification)
• Cloning, Molecular
• Entamoeba histolytica (immunology)
• Entamoebiasis (diagnosis)
• Enzyme-Linked Immunosorbent Assay
• Epitopes
• Humans
• Liver Abscess, Amebic (diagnosis, immunology)
• Molecular Weight
• Rabbits
• Recombinant Fusion Proteins (chemistry, immunology)